Social dynamics among mule deer and how they visit various environmental areas: implications for chronic wasting disease transmission

View/Open

Date

Author

ORCID

Type

Degree Level

Metadata

Abstract

This dissertation analyzes sociality patterns of mule deer (Odocoileus hemionus) and how they visit different localized environmental areas, two epidemiologically relevant sources of variability in chronic wasting disease (CWD) transmission dynamics. This dissertation seeks to answer questions such as what are the seasonal patterns of mule deer group formation and size, what factors can predict close-distance proximity and physical contacts between individuals, and in which environmental areas are different sex and age classes of deer found throughout the year. These questions are of great relevance in the study of a disease that efficiently transmits through animal-animal contact and prion contaminated environments.
Mule deer in Antelope Creek, a CWD endemic area in Saskatchewan, Canada, have been studied since 2006. I used genetic, behavioural, camera-trap, and high-resolution and high-frequency radio-telemetry data to address these questions. First, we learned that when mule deer showed clinical signs of the disease they were less likely to be reported in groups. Second, males were more likely to be found in close-distance proximity with other males in pre-rut, and with females in rut. Also, females tended to have more stable and longer lasting relationships with any other females than with males, whereas male-male relationships tended to be ephemeral. Third, individuals grouped more often with their close relatives, but the latter were not more likely to physically contact each other within groups. Lastly, grain spills were the sites most visited by deer and where they contacted the environment most often with either their mouths and antlers, or by defecating and urinating. Hence, grain spills could be of great importance for disease control, as they can be modified to reduce mule deer congregation, environmental prion contamination and transmission.
This dissertation describes several features of mule deer social behaviour, which advances our understanding of their sociobiology. These findings provide insight into how CWD may be transmitted in wild cervids and will be useful in the further development of spatially- and behaviourally-explicit dynamic epidemiological models to guide CWD management strategies.